Substituent effects in 1H and 13C nuclear magnetic resonance correlations of chemical shifts in para-substituted 5-arylmethylenehydantoins

Abstract

Substituent effects in para-substituted 5-arylmethylenehydantoins have been studied by correlations of ¹H and ¹³C chemical shifts with Hammett constants. In addition to the expected correlations for the ¹H chemical shift of the vinyl proton and the ¹³C chemical shift of the β-carbon C-5, good linear correlations are also obtained for the chemical shifts of the N-1 and N-3 protons which are respectively four and five atoms away from the benzene ring as well as for the α-carbon C-6.